Spinal fusion procedures may involve the remove of a herniated disk and cleaning all of the debris out of the disk space prior to introducing an implant such as a cage or the like and grafting material. To perform such procedures as minimally-invasive surgery (MIS), it can be difficult, if not impossible to remove all of the fragments of the disk or any other debris that might impede the proper insertion and placement of one or more implants and, optionally grafting material. One of the major causes of this difficulty is that access ports or other tubes used to allow the surgeon to access the surgical site place significant restrictions on the mobility of the instruments being used by the surgeon to remove the disk, disk fragments and debris.
U.S. Patent Application Publication No. 2014/0243604 provides a surgical access tube that is provided with oppositely positioned weakened distal portions that can be removed to afford lateral intrusions of the spinous process and facet, respectively, to allow placement of the access tube over the spinous process and facet during a surgical procedure. The break-away, weakened distal portions simplify the fitting of the access tube, making it easier to use than previous tubes that the surgeons had previously used after selectively resecting some portion of the distal end of the tube not having the weakened sections. A weakened proximal portion may also be provided to improve a range of angles for surgical instruments working through the access tube. The weakened proximal section is limited to a height of about 15-20 mm and weakened sections converge from a wider base opening (either at the distal end or proximal end of the access tube) to an arc base, presumably to avoid crack propagation and maintain rigidity of the access tube. Due to the limited height and sweep angle defined by the weakened proximal section, angulation of instruments is limited to only about 25 degrees, possibly up to 30 degrees. Further, the tube must be installed in a predetermined orientation relative to the spinous process and facet and therefore does not allow the tube to be rotated about its longitudinal axis, thereby further limiting the ability to angulate instruments inserted therethrough. It would be desirable to provide solutions that would allow a greater range of angulation of instruments used in an access tube.
U.S. Pat. No. 7,594,888 discloses expandable ports that can be used in minimally invasive surgery. The expandable ports are typically enclosed along the lengths thereof, even after expansion, but some embodiments, such as in FIGS. 17, 18, 29 and 23 result in proximal and distal gaps at the location of expansion. Such gaps are merely the result of the mechanism used to expand the tube. Further, these embodiments retain an impediment such as a mechanism intermediate the proximal and distal gaps which would limit angulation much in the same way described above that angulation is limited in U.S. Patent Application Publication No. 2014/0243604.
There is a need for improved products and methods that allow greater mobility of surgical instruments during MIS surgery, particularly MIS spine surgery.
There is a need for improved products and methods that provide greater, more consistent visibility during MIS surgery, eliminating or significantly reducing shadows and “dead spots” in the visibility field.